Barack taps into the inspiration of his followers to both lead, and be guided by, them in his bid for the presidency.
He has already worked with grassroots in the community when he was younger, and recognise the possibilities of building on the public perception of grassroots ownership in the campaign, particularly to foster a sense of pride within them as part of this dramatic change in American politics.
There is no feeling like being there at the start of something exciting, with huge potential, and believing you can also make a difference to its outcome.
As a politician and senator, he has also seen first hand the effects of big public interest bodies on government, especially caused by the huge donations these interests make, and wants to be free from obligations to be his own man when he is elected; to avoid being in the favour of any select group once he is in power.
Moreover, Barack Obama is the new guy on the block.
He has not had time to build up a political reputation like his rivals in the race and has probably assessed that, if he takes the people with him in grassroots support, he will be in a far more powerful position to claim to represent their aspirations than if he were backed by selected big businesses and interests groups.
Barack Obama seems genuinely sincere and honest about his desire for a more inclusive, one-nation America and the grassroots campaign appears to be the most effective way to achieve this, to draw as many cultures and viewpoints as possible behind him and to take America in the spirit of collaboration and consensus that is his ideal.
I believe that it is working already mainly because that approach is not a gimmick.
The people know he is being sincere, they can see the results already from their own efforts and participation and that encourages and inspires them to fall behind his charismatic persona to help him realize the dream.